[PATCH v2 4/4] power: reset: Add new driver for RZ/V2M PWC poweroff

Fabrizio Castro
2022-12-21T21:10:40Z

The RZ/V2M PWC IP controls external power supplies and therefore
can turn the power supplies off when powering down the system.

Add driver to poweroff the system.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
---

v1->v2: Dropped OF match table and syscon as a result of the change in
DT model

drivers/power/reset/Kconfig | 9 ++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/rzv2m-pwc-poweroff.c | 67 ++++++++++++++++++++++++
3 files changed, 77 insertions(+)
create mode 100644 drivers/power/reset/rzv2m-pwc-poweroff.c

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index a8c46ba5878f..1fcf691ae68e 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -303,4 +303,13 @@ config POWER_MLXBF
help
This driver supports reset or low power mode handling for Mellanox BlueField.

+config POWER_RESET_RZV2M_PWC
+ tristate "Renesas RZ/V2M PWC Power OFF support"
+ depends on MFD_RZV2M_PWC_CORE || COMPILE_TEST
+ help
+ The RZ/V2M PWC IP controls external power supplies and therefore can
+ turn the power supplies off when powering down the system.
+ Enable this driver when PWC is in control of the system power supplies
+ and it's the preferred way to shutdown the system.
+
endif
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 0a39424fc558..f05a8abff2eb 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -36,3 +36,4 @@ obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o
obj-$(CONFIG_POWER_MLXBF) += pwr-mlxbf.o
+obj-$(CONFIG_POWER_RESET_RZV2M_PWC) += rzv2m-pwc-poweroff.o
diff --git a/drivers/power/reset/rzv2m-pwc-poweroff.c b/drivers/power/reset/rzv2m-pwc-poweroff.c
new file mode 100644
index 000000000000..f5bc383c22e1
--- /dev/null
+++ b/drivers/power/reset/rzv2m-pwc-poweroff.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Renesas Electronics Corporation
+ *
+ * Reset driver for Renesas RZ/V2M External Power Sequence Controller (PWC)
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include "../../mfd/rzv2m-pwc.h"
+
+#define PWC_PWCRST_RSTSOFTAX 0x1
+#define PWC_PWCCKEN_ENGCKMAIN 0x1
+#define PWC_PWCCTL_PWOFF 0x1
+
+struct rzv2m_pwc_poweroff_priv {
+ void __iomem *base;
+ struct device *dev;
+};
+
+static int rzv2m_pwc_poweroff(struct sys_off_data *data)
+{
+ struct rzv2m_pwc_poweroff_priv *priv =
+ (struct rzv2m_pwc_poweroff_priv *)data->cb_data;
+
+ writel(PWC_PWCRST_RSTSOFTAX, priv->base + PWC_PWCRST);
+ writel(PWC_PWCCKEN_ENGCKMAIN, priv->base + PWC_PWCCKEN);
+ writel(PWC_PWCCTL_PWOFF, priv->base + PWC_PWCCTL);
+
+ mdelay(150);
+
+ dev_err(priv->dev, "Failed to power off the system");
+
+ return NOTIFY_DONE;
+}
+
+static int rzv2m_pwc_poweroff_probe(struct platform_device *pdev)
+{
+ struct rzv2m_pwc_priv *pdata = dev_get_drvdata(pdev->dev.parent);
+ struct rzv2m_pwc_poweroff_priv *priv;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->base = pdata->base;
+ priv->dev = &pdev->dev;
+
+ return devm_register_power_off_handler(&pdev->dev, rzv2m_pwc_poweroff,
+ priv);
+}
+
+static struct platform_driver rzv2m_pwc_poweroff_driver = {
+ .probe = rzv2m_pwc_poweroff_probe,
+ .driver = {
+ .name = "rzv2m_pwc_poweroff",
+ },
+};
+module_platform_driver(rzv2m_pwc_poweroff_driver);
+
+MODULE_ALIAS("platform:rzv2m_pwc_poweroff");
+MODULE_SOFTDEP("pre: rzv2m_pwc");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fabrizio Castro <castro.fabrizio.jz@renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/V2M PWC power OFF driver");
--
2.34.1